Performance of a Phase Transition Extraction (PTE) Column with Inclined Settlers

摘要

The mass transfer performance and flooding limitations of liquid-liquid counter-current two-phase flow in Phase Transition Extraction (PTE) column are investigated both experimentally and theoretically. In the experiments, the effect of the settlers' inclination on the onset of flooding in non-isothermal PTE column was investigated. The effects of inclination on the counter-current flow characteristics and mass transfer rates were also studied in isothermal pipe flow. It was found that flooding conditions in the column can be postponed by using off-horizontal settlers. This led to the development of a novel structure of a PTE column with improved throughputs. In addition, the effect of the new configuration on the mass transfer performance of the PTE column was tested in the single- and two-stage columns. The mass transfer performance experiment shows that the novel structure of the column still preserves the advantages of the original PTE column. A model is suggested for predicting flooding conditions in the PTE column. It combines a recently developed two-fluid model with improved theory-based closure relations for laminar stratified flow, with a non-isothermal model for evaluating the composition of the solvents in the mixing section and the internal streams in the column. The results of the combined model favorably predict the experimental flooding flow rates.